no need for flux-pen with this solder,THIS IS high activity, rosin activated cored wire is excellent for instant wetting action. Although "44" is an RA-based material, the residues are non-corrosive if left uncleaned. WIRE DIAMETER .031 ALLOY 60% TIN 40% LEAD,# Melting range: 361-374°F (183-190°C) FREE SHIPPING TO US,CA!!!
# Core flux type: RA